//=============================================================================
// System  : MatchKit
// File    : XmlPattern.cs
// Author  : Fabio Bussu  (matchkit@fabiobussu.it)
// Updated : 04/16/2013
// Note    : Copyright 2013, Fabio Bussu, All rights reserved
//
// This code is published under the Microsoft Public License (Ms-PL). A copy
// of the license should be distributed with the code.  It can also be found
// at the project website: http://matchkit.codeplex.com. This notice, the
// author's name, and all copyright notices must remain intact in all
// applications, documentation, and source files.
//
// Version     Date     Who  Comments
// ============================================================================
// 1.0.0.0  04/16/2013   FB  First draft
//=============================================================================
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Xml;

namespace MatchKit.Patterns
{
	/// <summary>
	/// Provides the logic to match an xml.
	/// </summary>
	/// <threadsafety static="true" instance="false" />
	/// <serialization binary="true" contract="true" />
	/// <conceptualLink target="cb785773-b793-4cc4-acc4-6688cdb226b2" />
	/// <conceptualLink target="0a06b2a9-5f58-409a-ba62-639cfd77bca7" />
	#if DC
	[DataContract]
	#endif
	#if SZ
	[Serializable]
	#endif
	public sealed class XmlPattern : BasePattern
	{
		/// <inheritdoc />
		protected override Match OnMatch(MatchContext context)
		{
			if (context.Current != '<')
				return Error(context);

			var stream = new StringReader(context.RemainingContent);
			using (var reader = XmlReader.Create(stream, new XmlReaderSettings { IgnoreComments = true, IgnoreProcessingInstructions = true, IgnoreWhitespace = true }))
			{
				var prop = reader.GetType().GetProperty("DtdParserProxy_CurrentPosition"
					, System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.FlattenHierarchy);

				try
				{
					if (!reader.Read())
						return Error(context);
					if (reader.NodeType == XmlNodeType.XmlDeclaration)
						if (!reader.Read())
							return Error(context);
					using (var subtree = reader.ReadSubtree())
						while (subtree.Read()) ;
				}
				catch (Exception ex)
				{
					return Error(context, ex.Message);
				}

				var endat = (int)prop.GetValue(reader, null);
				context.NextFor(endat);
			}

			return Success(context, MatchedString.Value);
		}

		/// <inheritdoc />
		public override string HelpString
		{
			get { return "Xml"; }
		}
	}
}
